This is a note to let you know that I've just added the patch titled
net/sched: cls_fw: Fix improper refcount update leads to use-after-free
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-sched-cls_fw-fix-improper-refcount-update-leads-to-use-after-free.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 0323bce598eea038714f941ce2b22541c46d488f Mon Sep 17 00:00:00 2001
From: M A Ramdhan <ramdhan@xxxxxxxxxxx>
Date: Wed, 5 Jul 2023 12:15:30 -0400
Subject: net/sched: cls_fw: Fix improper refcount update leads to use-after-free
From: M A Ramdhan <ramdhan@xxxxxxxxxxx>
commit 0323bce598eea038714f941ce2b22541c46d488f upstream.
In the event of a failure in tcf_change_indev(), fw_set_parms() will
immediately return an error after incrementing or decrementing
reference counter in tcf_bind_filter(). If attacker can control
reference counter to zero and make reference freed, leading to
use after free.
In order to prevent this, move the point of possible failure above the
point where the TC_FW_CLASSID is handled.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: M A Ramdhan <ramdhan@xxxxxxxxxxx>
Signed-off-by: M A Ramdhan <ramdhan@xxxxxxxxxxx>
Acked-by: Jamal Hadi Salim <jhs@xxxxxxxxxxxx>
Reviewed-by: Pedro Tammela <pctammela@xxxxxxxxxxxx>
Message-ID: <20230705161530.52003-1-ramdhan@xxxxxxxxxxx>
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: SeongJae Park <sj@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/sched/cls_fw.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
--- a/net/sched/cls_fw.c
+++ b/net/sched/cls_fw.c
@@ -225,11 +225,6 @@ static int fw_set_parms(struct net *net,
if (err < 0)
return err;
- if (tb[TCA_FW_CLASSID]) {
- f->res.classid = nla_get_u32(tb[TCA_FW_CLASSID]);
- tcf_bind_filter(tp, &f->res, base);
- }
-
#ifdef CONFIG_NET_CLS_IND
if (tb[TCA_FW_INDEV]) {
int ret;
@@ -248,6 +243,11 @@ static int fw_set_parms(struct net *net,
} else if (head->mask != 0xFFFFFFFF)
return err;
+ if (tb[TCA_FW_CLASSID]) {
+ f->res.classid = nla_get_u32(tb[TCA_FW_CLASSID]);
+ tcf_bind_filter(tp, &f->res, base);
+ }
+
return 0;
}
Patches currently in stable-queue which might be from ramdhan@xxxxxxxxxxx are
queue-4.14/net-sched-cls_fw-fix-improper-refcount-update-leads-to-use-after-free.patch
